Apt-mirror-updater

---------------------------

**Significant changes:**

- Updated the releases bundled in the :mod:`~apt_mirror_updater.releases`
module to include the following:

- Ubuntu 20.10 (Groovy Gorilla)
- Ubuntu 21.04 (Hirsute Hippo)
- Ubuntu 21.10 (Impish Indri)

- Relaxed the :pypi:`beautifulsoup4` requirement to facilitate Python 2
compatibility (release 4.9.3 was the last to support Python 2 whereas
our requirements insisted on >= 4.4.1).

**Miscellaenous changes:**

- Updated the :func:`~apt_mirror_updater.releases.parse_version()` documentation
to refer to :class:`decimal.Decimal` instead of "a floating point number" (to
avoid any confusion).

.. _Release 7.3: https://github.com/xolox/python-apt-mirror-updater/compare/7.2...7.3

---------------------------

Add support for `Elementary OS`_ (suggested in `issue 10`_).

Because Elementary OS is based on Ubuntu the new backend is nothing more than a
thin wrapper for the Ubuntu backend. Its most significant content is a data
structure with known Elementary OS releases and how they map to Ubuntu.

.. _Release 7.2: https://github.com/xolox/python-apt-mirror-updater/compare/7.1...7.2
.. _Elementary OS: https://en.wikipedia.org/wiki/Elementary_OS
.. _issue 10: https://github.com/xolox/python-apt-mirror-updater/issues/10

---------------------------

After Ubuntu 14.04 went EOL it became clear that when a release goes EOL and
when it is archived (moved from the package mirrors to the old-releases
environment) can differ by a year...

This release of apt-mirror-updater acknowledges this distinction in the code
and properly handles the situation where a release has already gone EOL but has
not yet been archived.

This was also reported in `issue 9`_ by a colleague and friend of mine.

.. _Release 7.1: https://github.com/xolox/python-apt-mirror-updater/compare/7.0...7.1
.. _issue 9: https://github.com/xolox/python-apt-mirror-updater/issues/9

---------------------------

This is a maintenance release that (primarily) updates Python compatibility.

**Backwards incompatible changes:**

- Python 3.7 and 3.8 are now officially supported.

- Python 2.6 and 3.4 are no longer supported.

- Added ``python_requires`` to ``setup.py`` to aid :pypi:`pip` in version
selection given these compatibility changes.

**Significant changes:**

- Updated the releases bundled in the :mod:`apt_mirror_updater.releases` module
to include the following:

- Ubuntu 19.04 (Disco Dingo)
- Ubuntu 19.10 (Eoan Ermine)
- Ubuntu 20.04 (Focal Fossa).

- Bug fix for "accidental tuple" in :func:`apt_mirror_updater.releases.parse_csv_file()`.

**Miscellaenous changes:**

- Spent some time stabilizing the test suite on Travis CI (tests were passing
for me locally but not on Travis CI because the mirror selection differed).
As a result the test suite got a bit slower, but it's not too bad.

- Move caching decorator to :pypi:`humanfriendly`.

- Fixed deprecation warnings emitted by recent :pypi:`humanfriendly` releases
and bumped requirements I authored that went through similar changes.

- Made :mod:`multiprocessing` usage compatible with coverage collection. Note
that I don't expect this to increase coverage, I just wanted to get rid of
the warnings 😇 (because warnings about harmless things are just as
distracting as more pertinent warnings).

- Default to Python 3 for local development (required by :pypi:`Sphinx` among
other things).

- Fixed existing :pypi:`Sphinx` reference warnings in the documentation and
changed the :man:`sphinx-build` invocation to promote warnings to errors (to
aid me in the discipline of not introducing broken references from now on).

.. _Release 7.0: https://github.com/xolox/python-apt-mirror-updater/compare/6.1...7.0

---------------------------

- Bug fix for Ubuntu keyring selection that prevented
``ubuntu-archive-removed-keys.gpg`` from being used.
- Bug fix for :func:`~apt_mirror_updater.releases.coerce_release()`
when given a release number.
- Moved pathnames of Debian and Ubuntu keyring files to constants.
- Added logging to enable debugging of keyring selection process.
- Added proper tests for keyring selection and release coercion.

.. _Release 6.1: https://github.com/xolox/python-apt-mirror-updater/compare/6.0...6.1

---------------------------

Enable the creation of Ubuntu <= 12.04 chroots on Ubuntu >= 17.04 hosts by
working around (what I am convinced is) a bug in :man:`debootstrap` which picks
the wrong keyring when setting up chroots of old releases. For more information
refer to issue `8`_.

I've bumped the major version number for this release because the highly
specific ``apt_mirror_updater.eol`` module changed into the much more generic
:mod:`apt_mirror_updater.releases` module. Also the ``release_label`` property was
removed.

.. _Release 6.0: https://github.com/xolox/python-apt-mirror-updater/compare/5.2...6.0
.. _8: https://github.com/xolox/python-apt-mirror-updater/issues/8